Wireless communication systems are being widely deployed in order to provide various kinds of communication services, such as voice or data. The object of the wireless communication systems enables a number of users to perform reliable communication with each other irrespective of their position and mobility. However, a wireless channel has an abnormal characteristic, such as path loss, noise, shadowing, fading due to multipath, intersymbol interference (ISI), or the Doppler effect due to mobility of user equipment. Accordingly, a variety of techniques for overcoming the abnormal characteristic of the wireless channel and increasing the reliability of wireless communication are being developed.
Meanwhile, the wireless communication system is a cellular system. The cellular system is configured to divide a service region into a number of cells each served communication services in order to overcome a restriction in the service region and a restriction in the number of users accommodated in the service region. However, users placed at the boundary between cells are subject to inter-cell interference because of interference signals generated from neighbor cells. Base stations are also subject to inter-cell interference because of interference signals generated from neighbor cells. Inter-cell interference is one of the major causes to restrict the performance of a wireless communication system. Inter-cell interference may result in the depletion of transmission and reception signals of cell boundary users, a reduction in throughput, transmission power consumption, etc. They cause several problems in the support of various services for cell boundary users, the maintenance of Quality of Service (QoS), and cell coverage. Accordingly, to solve the inter-cell interference problem and to improve the performance of a system become the important requirements of a next-generation wireless communication system. In systems, such as 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.16 (WiMAX), and IEEE 802-20, a variety of techniques for improving the performance of a system by overcoming inter-cell interference are being used.
The IEEE 802.16 standard provides a technique and protocol for supporting broadband wireless access. The standardization had been conducted since 1999 until the IEEE 802.16-2001 was approved in 2001. The IEEE 802.16-2001 is based on a physical layer of a single carrier (SC) called ‘WirelessMAN-SC’. The IEEE 802.16a standard was approved in 2003. In the IEEE 802.16a standard, ‘WirelessMAN-OFDM’ and ‘WirelessMAN-OFDMA’ are further added to the physical layer in addition to the ‘WirelessMAN-SC’. After completion of the IEEE 802.16a standard, the revised IEEE 802.16-2004 standard was approved in 2004. To correct bugs and errors of the IEEE 802.16-2004 standard, the IEEE 802.16-2004/Cor1 (hereinafter referred to as ‘IEEE 802.16e’) was completed in 2005 in a format of ‘corrigendum’. An IEEE 802.16m which is a new technique standard is being standardized based on the IEEE 802.16e. In the IEEE 802.16m system, the throughput of a cell boundary user is required to be twice that of the IEEE 802.16e system. In order to satisfy the requirement, plenty of parts of the IEEE 802.16e system have to be improved and a method of controlling inter-cell interference also needs to be improved.
Methods of controlling inter-cell interference may differ depending on the requirements and characteristic of a wireless communication system, and the performance thereof may differ. If the system knows interference information such as information about a neighbor cell from which inter-cell interference is generated and information about intensity of the inter-cell interference, the inter-cell interference may be controlled efficiently. Accordingly, there is a need for a method of transmitting an interference information signal for efficiently controlling inter-cell interference.